Portable electrical appliance



June 23, 1970 T; R, FLOWERS ET Al. 3,517,235

` PORTABLE ELECTRCAL APPLIANCE June 23, 1970 T. FLOWERS ET Ax. 3,517,235

PORTABLE ELECTRICAL APPQIANCE Filed Aug. 4, 1967 sheets-sheet 2 ZZ IZ F7 J4 51 j' 4g 4' 35 32 l j] g5 /25 29 l//I7\ 1"`y /uq T. R. FLOWERS ET AL June 23, 1970 3 Sheets-Sheet 3 Filed Aug. 4, 1967 4 j M a j? ,7M w 3\ 3 2 7 L 7L nu w, QNNNL 4 y .....wwwl IIL Il Il |\\.L Mw

United States Patent O 3,517,235 PORTABLE ELECTRICAL APPLIANCE Theodore R. Flowers, Fairfield, and Siegfried Godel, Norwalk, Conn., assignors to Sperry Rand Corporation,

New York, N.Y., a corporation of Delaware Filed Aug. 4, 1967, Ser. No. 658,446 Int. Cl. H02k 7/06 U.S. Cl. 310-80 11 Claims ABSTRACT F THE DISCLOSURE This disclosure is directed to a power driven, lightweight portable electrical appliance having output means comprising oppositely driven reciprocating hairbrush units removably mounted in spaced parallel .relationship on a self-contained handle-housing the casing is provided with a rearwardly extending manual hand grip and in which housing, is mounted a motor and reciprocating drive means to effect the oppositely reciprocating movement of the hairbrush work units.

BACKGROUND OF THE INVENTION Portable electrical appliances adapted to simplify a wide variety of daily household and personal tasks are achieving an ever increasing public acceptance. A need exists however, in the iield of personal grooming for a lightweight, convenient, portable electrical appliance for providing an effective brushing action and in particular an appliance for hair brushing and scalp massage. Power driven hairbrushes having vibrating or rotary brushes have been provided in the past however, these known devices have presented various problems in use. Among other difficulties encountered in these known devices is the provision of effective and economical means for providing a brushing and massaging action whereby twisted hair is effectively unsnarled as the user traverses the hair with the brush unit. Further in known devices wherein movement is imparted to the brushes, relatively complex drive mechanisms have been provided which not only increase the cost of the device but tend also to make the device unwieldly in use.

An object of the present invention is to provide a portable electrical appliance having novel means for effecting counter reciprocation of a pair of work units and which means is capable of a long useful life and quiet efficient operation.

Another object is to provide a novel portable hair grooming and massage appliance having an efficient positive drive system for simultaneously reciprocating a pair of detachable brush members in opposite directions within the same plane.

Another object is to provide novel means for detachably mounting a pair of brush units on the drive means of a portable electrical appliance.

A further object is to provide a novel hair grooming appliance wherein is provided low friction bearing means for supporting a pair of oppositely reciprocating brush members.

Another object is to provide an embodiment of the invention incorporating a removable brush unit cartridge containing a plurality of brush units wherein means are provided for ready removal of the cartridge from the appliance.

The present invention contemplates a novel portable electrical appliance having novel means for reciprocating a pair of driven output or work members in opposite directions. In one embodiment, the invention is incorporated in a hair grooming and massage appliance wherein the output members include a pair of brush units and which appliance incorporates a highly efficient self-con- 3,517,235 Patented June 23, 1970 ICC tained drive system powered by a small electric motor for effecting opposite reciprocation of the brush units through the drive system. The drive system includes a dual eccentric driven shaft provided with eccentric studs or posts continuously engaging follower slots in the reciprocating units driving the separate brush units. Power is applied continuously throughout the operating cycle t0 each eccentric post and thence to each slotted reciprocating follower unit providing smooth, positive reciprocating drive motion propelling each brush unit in both its forward and rearward direction, thus minimizing stress variations, shock loading, bearing wear and noise, resulting in a long useful life of quiet, eicient operation of the appliance.

The above and other objects and advantages of the present invention will appear more fully hereinafter from a consideration of the detailed description which follows; taken together with the accompanying drawings wherein two embodiments of the invention are illustrated.

In the drawings:

FIG. 1 is a top plan view of a portable electric hairbrush incorporating one embodiment of the present invention, partially cut away to show the position of its drive unit and brush support assembly.

FIG. 2 is a fragmentary side elevation view of the embodiment shown in FIG. 1, partially in section.

FIG. 3 is a fragmentary enlarged perspective view of a dual-eccentric drive shaft incorporated in the embodiment of FIGS. 1 and 2.

FIGS. 4, 5, and 6 are successive, cross-sectional end elevation views, taken along the lines indicated in FIG. 1, showing the brush support and drive assembly components of this embodiment.

FIG. 7 is a fragmentary exploded view showing the underside of several supporting and drive components shown in FIGS. 4-6.

FIG. 8, partially in section, is a fragmentary side elevation view of an alternative embodiment of the invention having a dual-rocker arm drive system incorporating a different form of dual-eccentric drive shaft to actuate reciprocating brush units mounted in a removable cartridge.

FIG. 9 is an enlarged fragmentary bottom view of the alternative drive system shown in FIG. 8.

FIG. 10 is a cross-sectional end elevation view of the embodiment shown in FIG. 8 taken along the line 10-10 in FIG. 8, and

FIG. ll is a fragmentary perspective view, partially cut away to reveal the internal construction and operation, of an inverted removable dual-brush unit cartridge adapted for cooperative engagement and convenient disengagement in the embodiment of the invention illustrated in FIGS. 8, 9, and 10.

GENERAL DESCRIPTION OF THE INVENTION As shown in FIGS. 1 and 2, a preferred embodiment of the invention includes a portable hollow housing preferably formed of molded plastic material in two mating parts, such as high impact polystyrene, acylonitrile butadiene styrene, or the like. As shown in the drawings, housing 12 includes a forward base portion 13 having a substantially flat supporting base wall or floor 14 (FIGS. 2, 4, 5 and 6). Supporting wall 14 lies within a recessed portion formed by a continuous housing wall 18 providing the end and sides of the housing 12 and in which recessed portions are disposed brush units 16 and 17.

Housing 12 thence extends rearwardly, past a switch aperture 19 enclosing a switch button 21, to form an elongated handle 22.

A separate, removable housing cap 23 preferably overlies the housing base 13 and its rearwardly extending portion 22, to both of which it is firmly secured by suitable adhesive, or by housing screws. The housing cap 23 is provided with a rearward handle portion 24 overlying and mating with the handle portion 22 of the housing base 13 and forming therewith an elongated hollow handle for the appliance enclosing a power cord 26 or a battery of one or more electric storage cells 27 suitably connected to the drive motor of the device through the switch actuated by switch button 21, as indicated in FIGS. 1 and 2.

The support assembly for the pair of separate removable brush units 16 and 17 is illustrated in FIGS. 2, 4, 5, and 6. This support assembly includes a pair of similar brush unit support plates 28 and 29, each having both of their ends bifurcated to form a pair of longitudinally extending guide fingers 31 (FIGS. 1 and 4). The support plates 28 and 29 extend in longitudinally parallel relation side by side underlying the housing floor 14, where they are held by low friction plastic bearing blocks, preferably formed of nylon or Teflon.

As shown in FIGS. l, 2 and 4, a transverse forward Ibase bearing 32 is positioned Ibetween the underside of housing floor 14 andthe guide ngers 31 of the two support plates 28 and 29. The base bearing 32 is provided with two raised longitudinal guide lands 33 each fitting between the fingers 31 of one of the support plates 28 or 29, providing lateral guiding and positioning of the support plates for longitudinal reciprocating motion. A transverse forward cap bearing 34 extends across the ngers 31 of both `support plates 28 and 29, and -a pair of bearing assembly screws 36 mounted in suitable aligned aperture secure the cap bearing 34 to the respective lands 33 of the base bearing 32, anchoring the entire bearing assembly to the underside of the housing floor 14 to form -a sturdy, low-friction guide for the two support plates 28 and 29.

A similar transverse rearward base bearing block with guide lands and mating cap bearing is similarly held by assembly screws to the underside of housing 14 near switch 21, supporting the guide fingers at the rearward ends of the support plates 28 and 29, as indicated in dash lines in FIGS. 1 and 2.

As shown in FIG. 4, the transverse forward base bearing 32 with its lands 33 forms in cross section a dual-T- shaped guide member cooperating lwith the fingers 31 in the forked ends, of support plates 28 and 29 to guide the reciprocating longitudinal motion of these support plates, while minimizing their undesired movement toward or away from the housing floor 14 or in either lateral direction.

As shown in FIG. 5, the separate brush units 16 and 17 are each provided with bristle-holding bases provided with suitable anchoring apertures, preferably formed as cylindrical holes extending from the open face partway through the base of each brush unit, and dimensioned to receive and anchor the brush unit on mating split anchor studs 37 threadedly secured to one of the support plates 28 or 29. The degree of frictional engagement force anchoring the brush units to their respective mating split anchor studs 37 may be increased by spreading the forked ends of the split studs 37 to increase their resilient frictional engagement with the walls of the anchoring apertures, formed in the base of each brush unit 16 or 17. As shown in FIG. 2, a pair of the anchor studs 37 are mounted in each of the plates 28 and 29, providing two sturdy points of support for each of the brush units 16 and 17, while permitting their removal by the user merely by gripping ends of a brush unit 16 between thumb and forefinger, for example, and pulling it outwardly away from the floor 14 of the housing base 13, drawing the anchor apertures off the split studs 37.

DUAL-ECCENTRIC DRIVE SYSTEMS In the dual-eccentric drive system illustrated in FIGS. 1-7, the drive member is an eccentric drive shaft 38 shown in FIG. 3, provided with a crank assembly 39 extending from its end and comprising an inner crank pin 41 having its axis parallel to the axis of drive shaft 38 but eccentrically offset radially therefrom, and having its outer end integrally connected by a crank arm 42 to an outer pin 43 integrally extending axially outward from the opposite end of crank arm 42 and having its axis parallel to that of drive shaft 38 and radially offset eccentrically therefrom in the direction opposite to the eccentric offset crank pin 41, all as shown in FIG. 3.

Reciprocating movement of the support plate 28 is produced by the action of the follower plate 44, shown in FIG. 1, which is generally rectangular in shape with one side secured by rivets or the like to the upper side of the support plate 28 near its center and extending` transversely beyond the central edge of the support plate 28 to overlie a portion of the adjacent support plate 29. The adjacent edges of plates 28 `and 29 are cut away in semicircular recessed cut-outs 46, as shown in FIG. 1, providing space for the rotation of the crank assembly 39 mounted at the lower end of the drive shaft 38.

A similar follower plate 47 is secured Iby rivets or the like to the underside of the adjacent support plate 29, as shown in FIGS. l, 2 and 7. Centrally positioned in each follower plate is a transverse lateral central slot 48 serving as a follower slot, in sliding driving engagement with one of the crank pins of drive shaft 38.

Thus, as shown in the drawings, the crank assembly 39 of drive shaft 38 is mounted for rotation in driving engagement with the two slots 48 in the follower plates 44 and 47. The inner crank pin 41 is in sliding, driving engagement with transverse slot 48 in the overlying follower plate 44 anchored to support plate 28; crank arm 42 revolves between the cut-out portions 46 in the space between support plates 28 and 29; and the outer crank pin 43 is mounted in sliding driving engagement within the slot 48 in the underlying follower plate 47 anchored to the support plate 29, all as shown in the assembly view of FIG. 2.

Crankshaft 38- is journalled for rotation in a gear box 49 mounted inside housing base 13. Keyed on drive shaft 38 is a driven bevel gear `S1 meshed in driving engagement with a drive gear 52 keyed to the shaft of a drive motor 53 adjacently mounted in housing base ,13. Motor 53 is connected by the switch actuated by button 21 to a source of power, which may be the cells 27 shown in dash lines in FIG. 1, or may be an external power source to which the device is connected by power cord 26.

In the preferred embodiment shown in FIGS. 1-7 the transverse slots 48 in the two follower plates 44 and 47 are substantially aligned in the same transverse plane when the two reciprocating sliding plates 28 and 29 are aligned side by side in their center positions. When the crank assembly 39 of drive shaft 38 engaging the two transverse drive slots 48 in the follower plates 44 and 47 revolves in its journal bearings in gear box 49 under the torque produced by motor 53 and transmitted to it by gears 52 and 51, the oppositely olf-set dual-eccentric crank pins 41 and 43 tend to move the two follower plates 44 and 47 in opposite longitudinal directions, producing opposite reciprocating movement of the two support plates 28 and 29, and thus producing the desired opposite longitudinal reciprocation of the two brush units 16 and 17 mounted on the support plates 28 and 29. The direction of rotation of the motor 53 and the drive shaft 38 is not material, since rotation in either direction produces the desired opposite, out-of-phase, reciprocating movement of the two brush units `16 and 17.

Since outer crank pin 43 is continuously engaged with slot 48 in the lower follower plate 47 secured to support plate 29, and since the inner crank pin 41 is also continuously engaged with transverse slot 48 in the upper follower plate 44 anchored to support plate 28, the slight friction developed between assembly 39 and the slots 48, and the additional slight friction produced between the linger ends of support plates 28 and 29 in sliding engagement with the forward bearing blocks 32 and 34 and with the corresponding rear bearing blocks, together provide a light continuous load which is added to a small friction load developed in the journal bearings of drive shaft 38 and the shaft of motor 53. These light friction loads provide a continuous and substantially constant torque load on the drive train of shaft 38, gears 51 and 52 and motor 53. Load fluctuations and shoe-k loads are substantially eliminated in the devices of this invention, producing smooth, quiet operation and minimizing bearing wear, by continuously converting the rotation of the shaft of motor 453 to smooth, linear, harmonic reciprocating motion of brush units 16 and 17. Accordingly, the devices of this invention provide an exceptionally long useful life. The reciprocating movement of brushes |16 and 17 with the small amplitudes provided by the small radial offset of crank pins 41 and 43 provides effective massage and mild stimulation for the users scalp, combined with highly effective untangling and smoothing of the hair.

In addition, separate buing pad units may be mounted in place of brushes 16 and 17, and the device may then be used for gentle polishing and bufling of any desired object, such as sterling silver holloware, stainless steel, copper or aluminum utensils, furniture to be waxed and polished, or the like.

REMOVABLE CARTRIDGE BRUSH UNITS In the alternative embodiment of the invention illustrated in FIGS. 8-ll, a brush cartridge 54 is removably engaged to the underside of housing base 13 beneath housing floor 14. Brush cartridge 454 preferably takes the shape of a flat rectangular box, as shown in the inverted perspective view of FIG. 1l, as well as in the crosssectional view of FIG. l where the cartridge is shown installed in the housing 13. Cartridge 54 thus comprises a rectangular base 56 provided with integral side walls 57 and a central guide wall 58, all extending in the longitudinal direction in which the brush units are designed to move.

Brush units 59 and 61, generally similar to brush units 16 and |17 are provided along their longitudinal edges with laterally projecting guide flanges 62 slidably engaged in guide slots 63 extending longitudinally along the free edges of side walls `57 and central guide wall 58, as shown in FIG. ll. Slots `63 thus anchor the brush units 59 and 61 against outward or lateral movement while supporting them for reciprocating sliding movement as described above. The bases of the side walls 57 of cartridge 54 are provided with dimples 64 positioned for resilient mating engagement with inwardly extending anchoring projections 66 formed on the inside face of a cartridge collar '6-7 forming an open enclosure adjacent to the underside of housing floor 1,4 in which the cartridge `54 is removably engaged to the housing. Both the cartridge S4 and the housing base 13 are preferably formed of resilient plastic material, permitting the cartridge 54 tobe slidably inserted into resilient clamping engagement, with the projections 66 protruding into the dimples 64 formed in both side walls 57 of cartridge '54, as indicated in FIGS. l0 and 11.

An easily disengageable reciprocating drive assembly designed to produce opposite reciprocating movement of the brush units 59 and 61 mounted in the cartridge 54 is shown in FIGS. 8-11. This alternative drive assembly includes a drive motor 68 having a drive gear 69 mounted on its motor shaft, positioned for rotation inside the parallel walls 71 of a gear box 72. A dual eccentric drive shaft 73, somewhat different from the drive shaft 38 of FIG. 3, is journaled in suitable apertures in Walls 71. A driven gear 74 is keyed on shaft 73 in driving engagement with the motor drive gear 69. Both ends of drive shaft 73 extend through their journal apertures in side walls 71 of the gear box 72, and the dual-eccentric, oppositely-offset crank pins of drive shaft 73 are formed by two parallel,

eccentrically offset shouldered screws 75 mounted in suitable threaded apertures formed in the ends of drive shaft 73.

Each of the screws 7S is displaced a short predetermined distance in opposite radial directions from the central axis of drive shaft 73, to provide the oppositely-offset, out-of-phase, dual-eccentric actuation required.

Bell-crank arms 77 and 78 are each pivotally joined by pivot screws 79 for reciprocating pivotal movement to the side walls 71 at points close to the transverse central plane of the brush units 59 and 61. Each of the bell-crank arms 77 and 78 is provided with a driven arm 81 incorporating a short radial slot 82 extending in a radial direction from the pivot screw 79. The shouldered eccentric screws 75 extending from opposite ends of drive shaft 73 are drivingly engaged respectively in these slots 82. Rotation of motor H68 driving gears 69 and 74 produces continuous rotation of drive shaft 73 and corresponding orbital rotation of the eccentrically mounted shouldered screws 75 about the axis of drive shaft 73, producing cycling, pivoting movement of bell cranks 77 and 78 about their pivotal anchor points at pivot screws 79.

Each of the bell cranks 77 and 78 is also provided with a driving arm 83 extending downward through a suitable hole in a floor aperture 84 formed in the housing floor 14, and thence through an aligned drive aperture 86 formed in the cartridge base 56 of cartridge 54. The driving arms 83 extend in a substantially radial direction from the pivot screws 79 toward the central portions of the perspective brush units 59 and 61, slidably mounted in the cartridge 54.

The tips of the two driving arms 83 are shaped for removable engagement with the bases of these brush units 59 and l61 concealed inside cartridge S4. In the embodiment shown in FIGS. 8-11, for example, the tips of these driving arms 83 are formed as tapered projections each mating with a central socket portion 87 of an elongated ilat leaf or strip socket spring 88 anchored to the concealed base of one of the brush units 59 or 61.

Pivoting reciprocating movement of the bell crank arms 77 and 78 about their pivot screws 79, produced by cycling rotation of the oppositely offset, dual-eccentric shouldered screws 7S mounted in the ends of rotating drive shaft 73, thus produces resulting reciprocating movement of the tips of driving arms 83. Since these tips of the driving arms are pivoting about pivot screw 79, their small-amplitude reciprocating movement occurs along `a circle having its center at pivot screws 79, and over small distances which may be said to lie substantially in a tangent plane perpendicular to the radius extending from each pivot screw 79 along its driving arm 83. This tangent plane passes through the socket portions 87 of socket springs 88, and reciprocating movement of driving arms 83 thus produces corresponding reciprocating movement of the brush units 59 and 61 to which the socket springs 88 are anchored, with the brush unit flanges 62 sliding in guide slots 63 in the housing 54.

Again in this embodiment of the invention the sliding friction of brush units 59 and 61 sliding in the guide slots 63 formed in the cartridge 54 and the additional friction of the drive system together comprise a continuous and substantially uniform torque load on the drive motor e68, minimizing the load variations and shock loading, and producing smooth quiet operation with minimum wear on the bearings and sliding surfaces of the drive system.

The opposite reciprocation of the brush units 16 and 17 and 59 and 61 produces dynamic balancing of the appliance in a significant degree, minimizing vibration and quivering of the appliance in the users hand. The reciprocating drive motion is transmitted directly to the object being buifed or brushed, such as the human hair, producing highly eicient cleaning and brushing of the hair, massage and stimulation of the scalp, and removal of dandruff, dust and foreign particles, all without un- 7 desirable vibratory movement or oscillation of this portable hair brushing appliance.

While the objects of the invention are efficiently achieved by the preferred forms of the invention described in the foregoing specification, the invention also includes changes and variations falling within and between the definitions of the following claims.

What is claimed is:

1. A portable electric appliance comprising:

(a) a housing,

(b) output means including a pair of work units,

(c) means for mounting said work units in reciprocable sliding engagement on the housing,

(d) dual eccentric drive means arranged within said housing and drivingly connected to said output means for driving said work units individually in out of phase reciprocating cyclic motion,

(e) a drive motor disposed in the housing and drivingly connected to the drive means, and

(f) said dual eccentric drive means including a rotatable drive shaft having oppositely offset crank pins thereon, follower members on said housing adapted for reciprocable movement in short paths of reciprocating movement, and means provided on said follower members forming follower slots each engaging one of said crank pins, and said driven work units mounted in reciprocating driving engagement with said follower members.

2. The appliance of claim 1, wherein said follower slots are elongated and extend in a direction substantially transverse to the direction of the reciprocating movement paths whereby rotation of said drive shaft produces orbital motion of the crank pins in the elongated slots causing said follower members to reciprocate along their movement paths.

3. The appliance of claim 1 wherein the crank pins are formed at the same end of the drive shaft, said follower members being juxtaposed with their follower slots substantially parallel, and being anchored to parallel-sliding captive reciprocating supporting slide plates on which the driven units are mounted.

4. The appliance of claim 1, wherein the crank pins are formed at opposite ends of a drive shaft and journalled for rotation between two reciprocable follower members.

5. A portable electrical brush appliance comprising:

(a) a housing including an elongated casing having a rear handle portion and a forward portion, a recess portion provided in said forward housing portion and including a supporting base wall,

(b) output means including a pair of work units,

(c) means for mounting said work units on the housing in said recess portion in reciprocal sliding engagement and including bearing means,

(d) said work units including a pair of spaced and parallel slide members having portions arranged within said bearing means,

(e) a brush member supported by each of said slide members in spaced and parallel relationship,

(f) latching means provided on said slide members and brush members for detachably securing said brush members to said slide members,

(g) dual eccentric drive means mounted in said for- Ward portion of the housing and extending through said supporting wall and operable to drive said slide members and their associated brushes in out of phase reciprocating motion within said recessed portion, and

(h) a drive motor secured to the housing and drivingly connected to the drive means.

6. The appliance of claim 5 wherein said latching means comprise recess means formed in the brush units and latching projections on said slide members seated in said recess means and resiliently engaging said brush units.

7. A portable electrical brush appliance comprising:

(a) a housing including an elongated casing having a rear handle portion and a forward portion, a recess portion provided in said forward housing portion and including a supporting base wall,

(b) output means including a pair of work units,

(c) means for mounting said work units on the housing in said recess portion in reciprocal sliding engagement and including bearing means,

(d) said work units including a pair of spaced and parallel slide members having portions arranged within said bearing means, said slide members comprising elongated plate members, a follower member secured to each of said plate members and having follower slots provided therein,

(e) a brush member supported by each of said slide members in spaced and parallel relationship,

(f) dual eccentric drive means mounted in said forward portion of said housing and extending through said supporting wall, said drive means including a drive shaft having spaced eccentric pins thereon each disposed in one of said follower slots and adapted to drive said follower members and said slide members and their associated brushes in out of phase reciprocating motion within said recess portion, and

(g) a drive motor disposed in the housing and drivin gly connected to the drive means.

8. A portable electric appliance, comprising:

(a) a housing,

(b) output means including a pair of work units, and a cartridge removably engageable on the housing, said work units comprising a pair of brush units arranged in spaced and parallel relationship within said cartridge,

(c) means for mounting said work units on the housing, and including bearing means in said cartridge for supporting said brush units for reciprocating sliding movement,

(d) dual eccentric drive means arranged within said housing and drivingly connected to said output means for driving said work units individually in out of phase reciprocating cyclic motion, and

(e) a drive motor secured to the housing and drivingly connected to the drive means.

9. A portable electrical hairbrush appliance comprising:

(a) a casing having wall portions defining a recess portion,

(b) output means including a pair of work units,

(c) means for mounting said work units on the casing in said recess portion in reciprocal sliding engagement and including spaced bearing means,

(d) said work units including a pair of spaced and parallel slide members having portions arranged within said spaced bearing means,

(e) brush means supported by each of said slide members in spaced and parallel relationship in said recess portion,

(f) drive means mounted in said casing and extending through a wall of said recess portion and operable to drive said slide members and their associated brush means in out of phase reciprocating motion in said recess portion,

(g) a drive motor disposed in the casing and drivingly connected to the drive means, and

(h) frictional latch means associated with said output means for detachably maintaining said brush means in said recess portion and operable to readily release said brush means therefrom.

10. The device of claim 9 wherein said brush means include elongated individual brush units disposed on said slide members and wherein said frictional latch means include studs on said slide members and corresponding holes in said brush units, said studs adapted to be detachably fitted in said holes and frictionally restrained therein.

11. The device of claim 9 wherein said output means includes a cartridge, said cartridge having portions disposed in said recessed portions, said work units com- 9 10 prising a pair of brush units arranged in spaced and FOREIGN PATENTS parallel relationship within said cartridge, and wherein 135 978 12/1933 Austria said frictional latch means are provided on the exterior 389285 3/1933 Great ritain surface of said cartridge and adjacent surface of the walls 9191397 3/1947 Fran of the recess portion and incl ude detent projections on 5 185,887 11/1936 Switzerland one of said surfaces disposed 1n recesses provided 1n the other Surface' References Cited MILTON o. HIRSHEIELD, Primary Examiner UNITED STATES PATENTS R. SKUDY, Assistant Examiner 1,769,796 7/1930 Lepage. 10 2,158,823 5/1939 Kehl .T 31o-80 U-S- Cl- X-R- 3,074,089 1/1963 Brown 310-83 74-50; S10-50, 90 

